Method for providing mobility to mobile node in packet transport network, packet transport network system and gateway switch

Abstract

A method for providing mobility of a mobile node in a packet transport network, and a packet transport network system are provided. The packet transport network system includes a plurality of gateway switches configured in a plurality of packet transport access networks to connect a packet transport core network and transmit/receive a packet to/from a certain terminal via a certain access switch. When the certain terminal moves, each gateway switch updates a tunnel mapping and management table according to the movement of the certain terminal, allocates a pre-set tunnel by using information included in the tunnel mapping and management table, and transmits/receives a packet to/from a counterpart terminal via the allocated tunnel. Thus, a packet loss and delay due to the influence of handover occurring when the mobile node moves between networks can be minimized and the handover procedure can be simplified.

1 . A method for providing mobility of a mobile node by a gateway switch of one of a plurality of packet transport access networks each having a gateway switch to be connected to a core network in a packet transport network, the method including:
 transmitting/receiving a packet between the mobile node and a counterpart node via a first tunnel established with a gateway switch of a packet transport access network in which the counterpart node is located;   transmitting a packet received via the first tunnel from the counterpart node to the mobile node;   setting and managing a logical tunnel mapping and management table between different gateway switches according to the movement of the mobile node;   establishing a second tunnel between a gateway switch of an adjacent packet transport access network to which the mobile node has moved and the gateway switch of the packet transport access network in which the counterpart node is located; and   transmitting/receiving a packet between the mobile node and the counterpart node via the established second tunnel.   
     
     
         2 . The method of  claim 1 , wherein the transmitting/receiving of a packet between the mobile node and the counterpart node via the first tunnel comprises:
 establishing the first tunnel with the gateway switch of the packet transport access network in which the counterpart node is located;   when a packet is received from the mobile node, encapsulating the received packet by using a tunnel ID; and   transmitting the encapsulated packet to the counterpart node via the first tunnel.   
     
     
         3 . The method of  claim 2 , wherein the encapsulating of the received packet by using the tunnel ID when the packet is received from the mobile node, comprises:
 selecting the tunnel ID by using a virtual LAN ID (VID) and a medium access control (MAC) address included in the tunnel mapping and management table; and   encapsulating the received packet by using the selected tunnel ID.   
     
     
         4 . The method of  claim 1 , wherein the transmitting/receiving of a packet between the mobile node and the counterpart node via the first tunnel comprises:
 when a packet is received from the counterpart node via the first tunnel, decapsulating the received packet; and   removing a tunnel header from the decapsulated packet and transmitting the tunnel header-removed packet to the mobile node.   
     
     
         5 . The method of  claim 1 , wherein the setting and managing of the logical tunnel mapping and management table comprises:
 when the mobile node moves to an adjacent packet transport access network, registering, by the mobile node, its location to a gateway switch of the adjacent packet transport access network; and   updating the tunnel mapping and management table.   
     
     
         6 . The method of  claim 1 , wherein the setting and managing of the logical tunnel mapping and management table comprises:
 when the mobile node receives a request for location registration from the gateway switch of the packet transport access network in which the mobile node was previously located, updating the tunnel mapping and management table;   notifying adjacent different gateway switches about the location movement of the mobile node; and   notifying the mobile node and the counterpart node about the changed matter.   
     
     
         7 . The method of  claim 6 , wherein the updating the tunnel mapping and management table comprises:
 adding a new MAC address to a pre-set tunnel in the tunnel mapping and management table for communication with the counterpart node, additionally registering a virtual LAN ID (VID), and deleting the MAC address from the existing tunnel of the tunnel mapping and management table.   
     
     
         8 . The method of  claim 1 , wherein the transmitting/receiving a packet between the mobile node and the counterpart node via the established second tunnel, comprises:
 when a packet is received from the mobile node, encapsulating the received packet by using a tunnel ID; and   transmitting the encapsulated packet to the counterpart node via the second tunnel.   
     
     
         9 . The method of  claim 8 , wherein the encapsulating of the received packet by using the tunnel ID when the packet is received from the mobile node, comprises:
 selecting the tunnel ID by using a virtual LAN ID (VID) and a medium access control (MAC) address included in the tunnel mapping and management table; and   encapsulating the received packet by using the selected tunnel ID.   
     
     
         10 . The method of  claim 1 , wherein the transmitting/receiving of a packet between the mobile node and the counterpart node via the second tunnel comprises:
 when a packet is received from the counterpart node via the second tunnel, decapsulating the received packet; and   removing a tunnel header from the decapsulated packet and transmitting the tunnel header-removed packet to the mobile node.   
     
     
         11 . A packet transport network system comprising:
 a plurality of access switches configured in a plurality of packet transport access networks connected to a packet transport core network and transmitting/receiving a packet to/from a certain terminal; and   a plurality of gateway switches configured in the plurality of packet transport access networks, connecting the packet transport access networks to the packet transport core network, and transmitting/receiving a packet to/from the certain terminal via a certain access switch,   wherein each gateway switch includes a tunnel mapping and management table, and when the certain terminal moves, each gateway switch updates the tunnel mapping and management table according to the movement of the certain terminal and allocates a tunnel for transmitting/receiving a packet to/from a counterpart node by using the information included in the tunnel mapping and management table.   
     
     
         12 . The system of  claim 11 , wherein each gateway switch adds a new medium access control (MAC) address to a pre-set tunnel in the tunnel mapping and management table for communication with the counterpart node, additionally registers a virtual LAN ID (VID), and deletes the MAC address from an existing tunnel of the tunnel mapping and management table. 
     
     
         13 . The system of  claim 11 , wherein when each gateway switch receives a packet, which is to be transmitted to a counterpart node, from a certain terminal, it encapsulates the received packet by using a tunnel ID, and when each gateway switch receives a packet to be transmitted to the certain terminal, it decapsulates the received packet and removes a tunnel header from the decapsulated packet. 
     
     
         14 . The system of  claim 13 , wherein each gateway switch selects the tunnel ID by using the MAC address and the VID included in its tunnel mapping and management table, and encapsulates the received packet by using the selected tunnel ID. 
     
     
         15 . A gateway switch comprising:
 an interface unit that provides an interface to transmit/receive a packet;   a packet processing unit that encapsulates a packet received from a certain terminal, which is to be transmitted to a counterpart node, by using a tunnel ID, and decapsulates a received packet, which is to be transmitted to the certain terminal, and removes a tunnel header from the decapsulated packet; and   a tunnel management unit that includes a tunnel mapping and management table, updates the tunnel mapping and management table if the certain terminal moves, and allocates a tunnel for transmitting/receiving a packet by using information included in the tunnel mapping and management table.   
     
     
         16 . The gateway switch of  claim 15 , wherein the packet processing unit selects the tunnel ID by using a MAC address and a VID included in its tunnel mapping and management table, and encapsulates the received packet by using the selected tunnel ID. 
     
     
         17 . The gateway switch of  claim 15 , wherein the tunnel management unit adds a new medium access control (MAC) address to a pre-set tunnel in the tunnel mapping and management table for communication with the counterpart node, additionally registers a virtual LAN ID (VID), and deletes the MAC address from an existing tunnel of the tunnel mapping and management table.